Hang in ThreadPool::process()

[edolstra]

[root@ike:~]# eu-stack -p 18408
PID 18408 - process
TID 18408:
#0  0x00007f5c2d9ef44f pthread_cond_wait@@GLIBC_2.3.2
#1  0x00007f5c2e1daccc std::condition_variable::wait(std::unique_lock<std::mutex>&)
#2  0x00007f5c2e6fcb1c nix::ThreadPool::process()
#3  0x00007f5c2ea52d46 nix::Store::queryMissing(std::set<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > const&, std::set<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >&, std::set<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >&, std::set<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >&, unsigned long long&, unsigned long long&)
#4  0x0000000000410afb opServe(std::__cxx11::list<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, std::__cxx11::list<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > >)
#5  0x000000000040bdfa main::{lambda()#1}::operator()() const
#6  0x00007f5c2ed038f2 nix::handleExceptions(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::function<void ()>)
#7  0x0000000000407557 main
#8  0x00007f5c2d663560 __libc_start_main
#9  0x000000000040777a _start
TID 18440:
#0  0x00007f5c2d9f34a7 do_sigwait
#1  0x00007f5c2d9f351d sigwait
#2  0x00007f5c2e7035c5 nix::signalHandlerThread(__sigset_t)
#3  0x00007f5c2e708d9d std::thread::_State_impl<std::_Bind_simple<void (*(__sigset_t))(__sigset_t)> >::_M_run()
#4  0x00007f5c2e1e06df
#5  0x00007f5c2d9e9234 start_thread
#6  0x00007f5c2d72b74f __clone

[copumpkin]

Any idea if this is related to the other hangs we've seen recently? #1573 or #1585

[copumpkin]

Is this fixed by fda7b95?

[edolstra]

Yes, I think so.